Opening the chemosensory world of the lobster, Homarus americanus

Abstract

The natural history of the American lobster, Homarus americanus H. Milne-Edwards, 1837, was described in detail as part of the general interest in marine biology in the late 19th century. A half-century ago, lobsters gained prominence in the biological analysis of underwater chemical sensing, using neurobiological, behavioral, and ecological approaches. Lobsters made us recognize different chemical sensing organs, each with their unique signal-filtering properties and behavioral functions, and they showed how they generate and control information currents for both odor dispersal and reception. This led to better understanding of the constraints that fluid motion places on odor signal analysis and sensor design. This, in turn, spurred construction of a lobster-inspired electronic nose to measure the temporal resolution of chemoreceptor organs used in odor plume analysis and tracking. Simultaneously, long-term field and naturalistic tank observations revealed their social structure involving sheltering, dominance fights, individual recognition by urine signals, courtship displays, cohabitation, and mating behavior. While most investigations focused on chemical signals, flow sensors were analyzed as part of antennule flicking and odor-flow coincidence detection. Mechanoreception plays an important role in smelling and tasting. Lobster vision contributes to opponent size estimates and recognition. Multisensory analysis will become increasingly important as is the chemical identification of the signals. Lobsters remain significant contributors to underwater sensory biology, influencing many other model systems, including other crustaceans, mollusks, sharks, and reef fish larvae. It has always been my privilege to work with so many inspiring students and colleagues.